@function map-has-nested-keys($map, $keys...) {
  @each $key in $keys {
    @if not map-has-key($map, $key) {
      @return false;
    }
    $map: map-get($map, $key);
  }
  
  @return true;
}
@function map-deep-get($map, $keys...) {
  @each $key in $keys {
    $map: map-get($map, $key);
  }
 
  @return $map;
}
@function z($layers...) {
  @if not map-has-nested-keys($z-layers, $layers...) {
    @warn "No layer found for `#{inspect($layers...)}` in $z-layers map. Property omitted.";
  }
 
  @return map-deep-get($z-layers, $layers...);
}